Need collapsible widget only but custom package not working

I just want to use the collapsible feature of jQuery mobile. Using the custom download interface I selected that widget, downloaded the code (two css and one js), and installed.

It's not working, tho, so I'm wondering if I'm missing another step? Another file(s)?

It looks like the "picker" selects the necessary dependencies, so I assume everything I need is included in the download?